In various embodiments, controlled heating and/or cooling conditions are utilized during the fabrication of aluminum nitride single crystals and aluminum nitride bulk polycrystalline ceramics. Thermal treatments may also be utilized to control properties of aluminum nitride crystals after fabrication.

A silicon carbide ingot producing method is provided. The method produces a silicon carbide ingot in which an internal space of a reactor is depressurized and heated to create a predetermined difference in temperature between upper and lower portions of the internal space. The method produces a silicon carbide ingot in which a plane of a seed crystal corresponding to the rear surface of the silicon carbide ingot is lost minimally. Additionally, the method produces a silicon carbide ingot with few defects and good crystal quality.

A silicon carbide single crystal manufacturing apparatus includes a crucible constituted by a crucible body and a crucible lid; and a base that is placed on the underside of the crucible lid and holds a silicon carbide seed crystal, wherein the base has a structure in which a plurality of graphite plates having anisotropy of the thermal expansion coefficient are laminated and bonded, and when viewed in a plan view from the lamination direction, in the plurality of graphite plates, the maximum directional axes of the thermal expansion coefficient between adjacent graphite plates are orthogonal to each other or the maximum directional axes intersect within an angle range of ±15° from orthogonal.

Provides a method for adjusting a thermal field of silicon carbide single crystal growth, and steps comprise: (A) screening a silicon carbide source, and filling into a bottom of a graphite crucible; (B) placing a guide inside the graphite crucible; (C) placing a rigid heat conductive material on the guide, so that a gap between the guide and a crucible wall of the graphite crucible is reduced; (D) fixing a seed crystal on a top of the graphite crucible; (E) placing the graphite crucible equipped with the silicon carbide source and the seed crystal in an induction high-temperature furnace used by physical vapor transport method; (F) performing a silicon carbide crystal growth process; and (G) obtaining a silicon carbide single crystal.

A method for producing a p-type 4H—SiC single crystal includes sublimating a nitrided aluminum raw material and a SiC raw material. Further, there is a stacking of a SiC single crystal, which is co-doped with aluminum and nitrogen, on one surface of a seed crystal.

A manufacturing method for a group-III nitride crystal, the manufacturing method includes: preparing a seed substrate; increasing temperature of the seed substrate placed in a nurturing chamber; and supplying a group-III element oxide gas produced in a raw material chamber connected to the nurturing chamber by a connecting pipe and a nitrogen element-containing gas into the nurturing chamber to grow a group-III nitride crystal on the seed substrate, wherein a flow amount y of a carrier gas supplied into the raw material chamber at the temperature increase step satisfies following two relational equations (I) and (II), y<[1−k*H(Ts)]/[k*H(Ts)−j*H(Tg)]j*H(Tg)*t (I), y≥1.58*10.sup.−4*(22.4/28)S*F(N)/F(T) (II), wherein k represents an arrival rate to a saturated vapor pressure of a group-III element in the raw material chamber, Ts represents a temperature of the raw material chamber, Tg represents a temperature of the nurturing chamber, H(Ts) represents a saturated vapor pressure of the group-III element at the temperature Ts in the raw material chamber, H(Tg) represents a saturated vapor pressure of the group-III element at the temperature Tg in the nurturing chamber, j represents a corrective coefficient, t represents a sum of gas flow amounts flowing into the nurturing chamber from those other than the raw material chamber, S represents a cross-sectional area of the connecting pipe, F(N) represents a volumetric flow amount of the nitrogen element-containing gas supplied into the nurturing chamber, and F(T) represents a sum of volumetric flow amounts of gases supplied into the nurturing chamber from those other than the raw material chamber.

Embodiments of the present disclosure generally relate to apparatus, systems, and methods for in-situ film growth rate monitoring. A thickness of a film on a substrate is monitored during a substrate processing operation that deposits the film on the substrate. The thickness is monitored while the substrate processing operation is conducted. The monitoring includes directing light in a direction toward a crystalline coupon. The direction is perpendicular to a heating direction. In one implementation, a reflectometer system to monitor film growth during substrate processing operations includes a first block that includes a first inner surface. The reflectometer system includes a light emitter disposed in the first block and oriented toward the first inner surface, and a light receiver disposed in the first block and oriented toward the first inner surface. The reflectometer system includes a second block opposing the first block.

A method for preparing a SiC ingot includes: disposing a raw material and a SiC seed crystal facing each other in a reactor having an internal space; subliming the raw material by controlling a temperature, a pressure, and an atmosphere of the internal space; growing the SiC ingot on the seed crystal; and collecting the SiC ingot after cooling the reactor. The wafer prepared from the ingot, which is prepared from the method, generates cracks when an impact is applied to a surface of the wafer, the impact is applied by an external impact source having mechanical energy, and a minimum value of the mechanical energy is 0.194 J to 0.475 J per unit area (cm.sup.2).

A SiC ingot includes: a main body including a first cross-sectional plane of the main body and a second cross-sectional plane of the main body facing the first cross-sectional plane; and a protrusion disposed on the second cross-sectional plane and including a convex surface from the second cross-sectional plane of the main body, wherein a first end point disposed at one end of the second cross sectional plane, a second end point disposed at another end of the second cross sectional plane, and a peak point disposed on the convex surface are disposed on a third cross-sectional plane of the main body perpendicular to the first cross-sectional plane, and wherein a radius of curvature of an arc corresponding to a line of intersection between the third cross-sectional plane and the convex surface satisfies Equation 1 below:
3D≤r≤37D  [Equation 1]
where r is the radius of curvature of the arc corresponding to the line of intersection between the third cross-sectional plane and the convex surface, and D is a length of a line of intersection between the first cross-sectional plane and the third cross-sectional plane.

The invention provides a method of detecting crystallographic defects, comprising: sampling wafer of an ingot in complying with a predetermined wafer sampling frequency; identifying crystallographic defects of the wafer to show the crystallographic defects of the wafer; characterizing observation of the crystallographic defects of the wafer and extracting a value characterizing the crystallographic defects; through a result of characterizing the crystallographic defects, obtaining a radial distribution of density of the wafer and categorizing the crystallographic defects; and obtaining an isogram of the crystallographic defects of the wafer to show a crystallographic defect distribution of the whole ingot according to the value characterizing the crystallographic defects and categories of the crystallographic defects. It is no need to break the ingot to obtain the crystallographic defect distribution of the whole ingot, through which the technology for growing the ingot may be effectively adjusted to obtain the ingot with required characteristics of defect.